PM2.5-Bound Organophosphate Flame Retardants in Hong Kong: Occurrence, Origins, and Source-Specific Health Risks

Xuemei Wang, Chin Wai Leung, Zongwei Cai, Di Hu*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

3 Citations (Scopus)


Organophosphate flame retardants (OPFRs) are emerging organic pollutants in PM2.5, which have caused significant public health concerns in recent years, given their potential carcinogenic and neurotoxic effects. However, studies on the sources, occurrence, and health risk assessment of PM2.5-bound OPFRs in Hong Kong are lacking. To address this knowledge gap, we characterized 13 OPFRs in one-year PM2.5 samples using gas chromatography–atmospheric pressure chemical ionization tandem mass spectrometry. Our findings showed that OPFRs were present at a median concentration of 4978 pg m–3 (ranging from 1924 to 8481 pg m–3), with chlorinated OPFRs dominating and accounting for 82.7% of the total OPFRs. Using characteristic source markers and positive matrix factorization, we identified one secondary formation and five primary sources of OPFRs. Over 94.0% of PM2.5-bound OPFRs in Hong Kong were primarily emitted, with plastic processing and waste disposal being the leading source (61.0%), followed by marine vessels (14.1%). The contributions of these two sources to OPFRs were more pronounced on days influenced by local pollution emissions (91.9%) than on days affected by regional pollution (44.2%). Our assessment of health risks associated with human exposure to PM2.5-bound OPFRs indicated a low-risk level. However, further source-specific health risk assessment revealed relatively high noncarcinogenic and carcinogenic risks from chlorinated OPFRs emitted from plastic processing and waste disposal, suggesting a need for more stringent emission control of OPFRs from these sources in Hong Kong.
Original languageEnglish
Pages (from-to)14289–14298
Number of pages10
JournalEnvironmental Science and Technology
Issue number38
Early online date11 Sept 2023
Publication statusPublished - 26 Sept 2023

Scopus Subject Areas

  • Chemistry(all)
  • Environmental Chemistry

User-Defined Keywords

  • Carcinogens
  • Flame Retardants
  • Hong Kong
  • Humans
  • Organophosphates
  • PM2.5 source apportionment
  • Particulate Matter
  • organophosphate flame retardants (OPFRs)
  • plastic processing and waste disposal
  • source-specific health risk assessment
  • source apportionment
  • PM


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